Apple’s OS X is the operating system that all modern Macs run on, and the latest version, OS X 10.11 called “El Capitan”, was released in September 2015.
Rather than a radical change of OS X, El Capitan is better described as an enhanced version of OS X Yosemite, in the same way that Snow Leopard was an enhancement to Leopard.
When you shake the mouse (or a finger on the Trackpad,) in El Capitan, the pointer briefly becomes huge, making it easier to find it. There are also other useful changes: better mission control, disk utility, mail, notes, split view and photo functions.
There are also an increasing number of other Apple software from other software developers available. Find the latest Apple software deals and reviews here.